I have been acquiring different hollowing tools for urns and HF's. I recently bought a slightly used Sorby Swan Neck Tool, and the cutter appears to have been ground to a very shallow undercut, almost like a scraper with the bur on the top surface. I tried it yesterday, and even at dead center the cutting is not happening. I will post photos of it later when I get home. I am not sure if the previous owner custom made this cutter, because I don't find anything like it online. All of my previous cutters and ones used at JCC Folk School had a pretty good undercut, similar to a bowl gouge.